Orange Book Blog

Tyco Healthcare Group LP v. Mutual Pharm. Co., No. 2010-1513 (Fed. Cir. 2011)

   by Scott P. McBride

RESTORIL (temazepam) is a hypnotic (sleep-inducing) drug marketed for the treatment of insomnia.  In a decision last month, the Federal Circuit affirmed the invalidity of two claims of U.S. Patent No. 5,211,954 directed to temazepam formulations.  Claim 1 recites:

A hard gelatin capsule containing a temazepam formulation consisting essentially of 6 to 8 milligrams of crystalline temazepam having a surface area of from 0.65 to 1.1 m2/g and 95% of the temazepam having a particle size of less than 65 microns in admixture with a pharmaceutically acceptable carrier therefor.

Claim 2 "is identical except that it recites a composition containing 7.5 milligrams of crystalline temazepam."

In 2006, Mutual filed an ANDA for a generic version of 7.5 mg temazepam capsules, after which Tyco filed suit for infringement of the '954 patent.  In 2009, after Mutual received tentative FDA approval of its ANDA, Tyco moved for a preliminary injunction, which was denied due to "uncontroverted evidence" of no literal infringement due to the "surface area" limitation.

In an opinion last year, District Judge Chesler (D.N.J.) concluded on summary judgment that the two asserted composition claims were invalid for obviousness.  Judge Chesler noted that (1) RESTORIL capsules had been sold in the United States in 15 mg and 30 mg dosages more than a year before the 1986 priority date of the '954 patent, (2) a 1983 volume of the British National Formulary, a UK medical reference book, directed physicians to the use of temazepam at a dosage between 5 and 15 mg for the treatment of insomnia in the elderly, and (3) it was undisputed that "physicians always seek to prescribe the lowest effective dose of any medication, particularly hypnotics such as temazepam."

In affirming, the Federal Circuit noted that, when Tyco's predecessor filed a Supplemental NDA with the FDA for manufacture and sale of 7.5 mg temazepam capsules within the scope of both '954 claims, the application stated that:

[t]he formulation and manufacture of RESTORIL Capsules, 7.5 mg are similar to that used for the 15 and 30 milligram capsules . . . .  The [7.5 mg] formulation differs only in the reduction of the dose.  . . .  The capsule manufacturing method is exactly the same as has been described for the currently marketed doses.

The Federal Circuit stated, "[g]iven that uncontested description, the only limitation of the two '954 claims that was not fully disclosed by the prior art RESTORIL capsules is the lower dosage of temazepam."

The district court and the Federal Circuit relied on, among other things, the 1983 British National Formulary book.  The British National Formulary book stated that, for temazepam, the dose for "elderly patients [could be] 5-15 mg."  According to the district court, "[t]his entry plainly tells one of skill in the art to treat insomnia in the elderly by administering a dose in the range of 5 to 15 mg."  Moreover, the summary judgment record included evidence of a 1984 statement by an FDA representative to a group that included the named inventor of the 954 patent, that "the doses proposed in [certain] studies may be too high, [given] that in Great Britain, temazepam doses from 5-15 mg are recommended for geriatrics."

The Federal Circuit stated that where there is a range disclosed in the prior art, and the claimed invention falls within that range, the claim is presumed obvious.  That presumption is rebuttable either by a showing that the prior art taught away from the invention or by a showing of new and unexpected results. 

The Federal Circuit did not accept Tyco's arguments that the prior art taught away from the claimed invention or that secondary considerations of new and unexpected results and commercial success permitted a conclusion of non-obviousness.  The Federal Circuit also rejected, as "silly," one assertion made by Tyco's counsel at oral argument that the language "5-15 mg" did not actually disclose a range of doses (even though Tyco's expert had called it a "range").

Regarding that same range, the Federal Circuit also concluded that even if some of the references in the record taught away from the claimed dose generally, those teachings did not undermine the teachings in the British National Formulary book that related to the dosage in elderly patients. 

Finally, the Federal Circuit acknowledged, as correct, Tyco's expert's statements that the British National Formulary book (1) "nowhere states that a temazepam dose of 5 mg, 6 to 8 mg, or 7.5 mg, is effective in treating insomnia," (2) nor does it "state that 7.5 mg was effective," and (3) the British National Formulary book provides "[n]o clinical or statistical evidence . . . demonstrating that a dose within a range of 5-15 mg would work" in treating insomnia.  But the Federal Circuit also concluded that these observations do not undermine the district court's conclusions as to obviousness because the 954 patent's composition claims do not discuss the intended use of the capsules in a particular treatment regimen.